They all changed their size. Megatron and Omega Supreme were just the most drastic. Omega Supreme was the size of a city how the hell did he fit in Teletraan I? Also where did Primes trailer go when he transformed.

They all changed their size. Megatron and Omega Supreme were just the most drastic. Omega Supreme was the size of a city how the hell did he fit in Teletraan I? Also where did Primes trailer go when he transformed.

Don't forget the City Transformers, Metroplex and Trypticon.

Tryp was essentially the MechaGodzilla of the Transformers. But oh boy...he was dumb as ****.

We're starting to get into Transformers territory here.
For the record, it always troubled me how Megatron could change his mass when he transformed (seemingly)

The Transformers received the art of transformation and energy manipulation from their god, Primus, and transferring mass to energy and back again has been part of Cybertronian culture for millions of years in the form of Energon, their most precious resource.

Energon is energy in a physical form (solid, liquid, gas), and according to Transformers lore, Energon is what gives them their strength, allows them to transform their shapes, but also change their mass and size.